ATL: SALLY - Models

[Hypercane_Kyle]

Yes, but the Euro/GFS won't resolve this as a potential hurricane threat until it's actually a hurricane. Best to focus on track now.

I guess that’s why i question them...are the just west because they see it as staying weak. Maybe that’s what happens but how much of their track is the product if then resolving a weak storm

They're not weak per se'. They take it to Cat 1. HWRF is also in their neighborhood though much, much stronger. NAMs as well.

Looking at the Hi-res Euro, strongest winds I could find were like 45 knots.

[Steve]

Seems strange all things - and pressure considered. 45 knots is still powerful, but it's hardly the 110 HWRF showed. Based on what it is now and what it is likely to be Monday afternoon, it's probably somewhere in the middle.

[kevin]

Just saw in the discussion thread that recon measured 1000 mbar and an estimated 52 kts SFMR. If we look at what yesterday's 18z models (12z for CMC) forecasted for now (I took the average of 06z/09z UTC data points) you get:

HWRF = 1000 mbar, 46 kts
HMON = 1002 mbar, 39 kts
GFS = 1003 mbar, 33 kts
ICON = 1004 mbar, 32 kts
CMC = 1005 mbar, 32 kts

Am I missing something or are all the models way too slow with intensifying Sally (even in the short term) besides HWRF? If so, that's very bad news.

[Hammy]

HWRF still doing fairly well with convection even out at 36 hours.

[eastcoastFL]

Seems strange all things - and pressure considered. 45 knots is still powerful, but it's hardly the 110 HWRF showed. Based on what it is now and what it is likely to be Monday afternoon, it's probably somewhere in the middle.

That’s about how I feel. It’s all going to depend if there’s any shear down the road in my opinion. She’s starting to get it together this morning and once she gets that core worked out she’ll be ramping up. Hopefully she takes a while to get her act together and runs out of time to become a strong hurricane. Either way it looks like someone is in for some serious flooding down the road no matter how strong it is.

[eastcoastFL]

HWRF still doing fairly well with convection even out at 36 hours.

https://i.imgur.com/jkwgDOA.png
https://i.imgur.com/kP7LorA.png

Hwrf has been really impressive this season with forecasting the structural and IR presentation

Let’s hope this part doesn’t verify

[eastcoastFL]

I think once Sally gets a more defined center the models may start to tick up on intensity. I’m looking at the shear map and there’s an anti cyclone over the GOM and not much shear at all. I’m having a hard time believing she won’t push at least a cat 2 in these conditions given that she’ll have another 60ish hours over water.

[eastcoastFL]

As expected models are starting to tick upwards on intensity now that Sally is more developed and picking up steam.

06z Icon coming into Nola in the 980s




06z HMON

[Javlin]

HMON has it coming in on top of mine and FrankP's house 88.9W we'll see if that verifies strange kick W after landfall(?)

[gatorcane]

06Z HWRF is much weaker for some reason:

[Shell Mound]

06Z HWRF is much weaker for some reason:

https://i.postimg.cc/T1g9Mqrt/hwrf-mslp-wind-19-L-fh0-48.gif

Based on simulated IR imagery, the UL anticyclone looks to be more displaced on the 06Z vs. the 18Z/00Z runs, resulting in much higher VWS.

[shiny-pebble]

 https://twitter.com/DerekOrtt/status/1305112485826039808

[Shell Mound]

https://twitter.com/DerekOrtt/status/1305112485826039808?s=19

I suspect that the 12Z run of the HWRF may be much more revealing, with new data ingested by then. Perhaps it will show the strongest solution yet.

[jlauderdal]

06Z HWRF is much weaker for some reason:

https://i.postimg.cc/T1g9Mqrt/hwrf-mslp-wind-19-L-fh0-48.gif

slow down, land interaction..cant be discounted but the bigger issue for New Orleans very well could be the precip

[Blown Away]

06Z HWRF is much weaker for some reason:

https://i.postimg.cc/T1g9Mqrt/hwrf-mslp-wind-19-L-fh0-48.gif

slow down, land interaction..cant be discounted but the bigger issue for New Orleans very well could be the precip

06z intensity guidance down this run with most barely reaching Cat 1 status... Kind of a weird angle going WNW a few hundred miles S of the NGOM Coast from Fl peninsula to central LA then a very sharp NE turn after landfall, that usually means increasing shear... Let’s see if NHC maybe backs off intensity a little today...

[kevin]

Didn't expect 06z HWRF to be so weak. Will be interesting to see the 12z run to see whether this was a fluke. Usually I'd feel pretty safe if even HWRF starts weakening, but it seems it initialized way too weak as far as I can see. The current intensity according to NHC is 996 mbar and yet the HWRF doesn't reach that pressure until 18 hours from now.

[eastcoastFL]

06Z HWRF is much weaker for some reason:

https://i.postimg.cc/T1g9Mqrt/hwrf-mslp-wind-19-L-fh0-48.gif

slow down, land interaction..cant be discounted but the bigger issue for New Orleans very well could be the precip

You nailed it. Whether there’s a major wind event or not the rainfall accumulation is going to be the kicker. We have multiple models now calling for 2-3ft of rain total in the Nola and SW MS areas. That’s not something you want to see for New Orleans

[TimSmith]

Just saw in the discussion thread that recon measured 1000 mbar and an estimated 52 kts SFMR. If we look at what yesterday's 18z models (12z for CMC) forecasted for now (I took the average of 06z/09z UTC data points) you get:

HWRF = 1000 mbar, 46 kts
HMON = 1002 mbar, 39 kts
GFS = 1003 mbar, 33 kts
ICON = 1004 mbar, 32 kts
CMC = 1005 mbar, 32 kts

Am I missing something or are all the models way too slow with intensifying Sally (even in the short term) besides HWRF? If so, that's very bad news.

This is very interesting & might have something to do with the initial data fed into the models, and I'd expect the 12z models we'll see this afternoon will give a much clearly picture. I'm not sure of the exact details, but if I'm not mistaken I believe the HWRF is more fine mesh mathematically about the center of the storm while the others are more wider sort of global. The issue here might be that the others were initially reading that yesterday afternoon was either over land or some interaction with land so didn't intensify as quickly, but really that "land" actually had fuel in it; this data of initial conditions is so so important as the underlying equations that model are extremely sensitive to small changes in their initial value conditions. Anyways, we'll get a much clearer picture comparing the 0z runs to today's 12z to look the trends...

[LowerAlabamaTider]

11AM from NHC has nudged landfall a tad further west. Looking like Sally May be headed to the Big Easy for sure.

[PTPatrick]

12z icon still offshore of the mouth at 51. At 63 drifting north just east chandeleur islands. This is why I don’t trust any real west model swings yet...when steering slows they can do anything. Waiting for 12z suite and guidance to help determine what all the family should do, this is a tough one.

Edit, ends in landfall Dauphin island at 72 hrs.